Hi again - the prélèvement social + fiscal (line 3) isn't a separate item, it's lines 1 (prélèvement social) and line 2 (prélèvement fiscal) totalled together, so it hasn't got to be added in again or you've accounted for them both twice!
Two more tiny comments: firstly the Chamber contribution, which you've got labelled as Chamber of Commerce but obviously for artisans it's actually the Chambre de Métiers, Chamber of Trades or whatever you want to call it (I think we would call it the Chamber of Industry in the UK) - might be helpful to any artisans looking at this to mention that, so they're not confused over which chamber they're contributing to.
Second comment you might decide not to bother with, but the prélèvement fiscal (line 2) is optional in the sense that in most cases you can opt to pay your income tax based on actual figures in the annual tax exercise, rather than at the flat rate as you go along. In fact some people (ie households with a high-ish total income, of which their ME earnings is only a small proportion) don't have the option of paying at the flat rate, they have to pay on actual earnings. Plus, if your earnings are below the tax-free allowance then obviously it makes no sense choose to pay tax at a flat rate if the alternative is paying no tax at all.
Sorry if I confused things by mentioning 66% in a previous post. That is nothing at all to do with your ME cotisations since they are all based on turnover. However for all other administrative purposes, the significant figure is not turnover but income. So for each category of activity (commerçant, artisan, services, profession libérale) they have worked out the average profit:expenses ratio of turnover, which for prof lib is 66:34, and this is the formula used by the tax office to calculate your annual 'income' from the turnover you declared. Eg if your chiffre d'affaires from prof lib activities as a micro is 10000, and that is all the household earns, then the household income figure would be 6600. That is the figure you would provide every time you are asked your annual income. So it's nothing to do with declaring your chiffre d'affaires and paying your cotisations, but it is an important figure nonetheless. And to go back to the income tax options: supposing you wanted to work out whether paying tax at the flat rate was advantageous to you or not, this is the figure you would look at to enable you to work out how much income tax you would have paid on that income in the annual tax exercise, and do the comparison. As a prof lib with a turnover of 10k your "income" of 6,600 would be below the tax threshold so it's a no-brainer, opting to pay flat rate tax is disadvantageous.
Hope that makes sense!